package easy;

public class Solution_268 {

    public static int missingNumber(int[] nums) {
        int count = 0;
        for (int i = 0; i < nums.length; i++) {
            count = count + i - nums[i];
        }
        return nums.length+count;
    }

    public static void main(String[] args) {
        System.out.println(missingNumber(new int[]{}));
    }
}
